Engine muffler



Dec. 3, 1935. J. c. KITTELL. 2,023,024

.ENG INE MUFFLER Fil'ed Aug. 29, 1931 ,8 INVENTOR.

J'uL/us a. KITTEL L A TTORNEY Patented Dec. 3, 1935 UNITED STATES PATENTOFFICE 2.023.024 ENGINE MUFFLER tion of California- Application August29, 1931, Serial No. 560,084

1 Claim.

My invention relates to mufflers for internal combustion engines, and ithas for a purpose the provision of a mufller which is characterized byits ability to muffle and control the liberation to atmosphere of theexhaust gases from an engine in such a manner as to reduce back pressureto a minimum, thereby increasing to a maximum the effective powerdelivered by the engine.

It is also a purpose of my invention to provide a mufiler having theaforementioned back pressure reducing property and yet adaptable to highspeed engines as well as to low speed and heavy duty engines.

A further purpose of my invention is the provision of the combination ofa muffler and a device for connecting the muiller to the intake manifoldof an engine so that at least a part of the exhaust gases are conductedto the engine cylinders to cause the unburnt gases to combine with thefresh fuel and to thus reduce consumption of the fresh fuel by theengine. Further, the reciprocal advantage is obtained of utilizing thesuction of the engine to relieve the exhaust gas pressure in the mufllerto further reduce back pressure, and also to increase the fluid pressurein the intake manifold for the purpose of lowering the resistanceoffered to the pistons on their suction strokes by the relatively lowpressure of the atmosphere air and thereby further increasing the enginepower developed.

I will describe only one form of muiiler, and one form of connectingdevice each embodying my invention, and will then point out the novelfeatures thereof in the claim.

In the accompanying drawing,

Fig. 1 is a view showing in side elevation one form of muiller and oneform of device for utilizing exhaust gases for fuel, each embodying myinvention, and both of which are shown in applied position to aninternal combustion engine.

Fig. 2 is a vertical longitudinal sectional view of the mulfiler.

Figs. 3 and 4 are sectional views taken on the lines 3-3 and 4-4,respectively, of Fig. 2, and looking in the directions of the arrows.

Fig. 5 is an enlarged sectional view of the valve element of theconnecting device shown in Fig. 1.

Referring specifically to the drawing, I have illustrated a muiiler,comprising a hollow and elongated body B having an inlet I5 at one endconnected to an exhaust pipe P so as to receive exhaust gases from aninternal combustion engine E, and an outlet I6 at the other end whichcommunicates with the usual outlet pipe II. A pipe I8 of relativelysmall-diameter is supported by arms I9 within the body B so as to bedisposed along the major axis of the body with one end extending intothe exhaust pipe P, and the opposite end spaced from the adjacent endwall of the body.

Surrounding a part of the pipe I8 is a second pipe 20 which is ofconical form with its larger end facing the exhaust pipe P and spacedfrom the adjacent end wall of the body, and supported concentrically ofthe pipe I8 by radiating arms 2|. The smaller end of the conical pipemerges into the pipe I8 where it is spot-welded or otherwise secured. Aport 22 is formed in the pipe I8 adjacent the small end of the pipe 20for the pur pose of permitting exhaust gases in the conical pipe to passinto the straight pipe.

Between the confronting ends of the pipes I1 and I8 are one or morefunnel shaped members supported in fixed position, one in advance of theother, by radiating arms 23. In the present instance, I have shown twosuch members 24 and 25 of different diameters at their larger ends, andprovided with outlet nozzles 24 and 25 at their smaller ends whichincrease in internal diameter from their points of connection with thefunnels to their free ends. These tapered nozzles are alined with thepipes I1 and I8, the outlet end of the pipe IB having a constrictednozzle 26 extending into the member 24.

As so far described, the mumer functions in its association with anengine, as follows;

Part of the gases traversing the exhaust pipe P enter the large end ofthe pipe 20. The remainder of the gases enter the muiller body in thatspace surrounding the pipes I8 and 20. Those gases entering the pipebeing of relatively high pressure traverse the pipe and are dischargedfrom the nozzle 26 at high velocity. From the nozzle they passsuccessively through the members 24 and 25, being finally dischargedinto the pipe II to atmosphere.

Constriction' of the nozzle 26 accelerates the velocity of the gases asemitted, and as discharged into the member 24, the gases produce asuction in the large end of the member which draws part of the gasesfrom the body into the member to combine with those from the nozzle 26.The gases now enter the nozzle 24 and in passing therethrough arepermitted to expand slightly, entering the member 25 at a somewhatreduced velocity. At this point the gases function to produce a suctionin the member 25 which draws gases from the body and over a larger areathan in the case of the member 24, and which gases are forced into thenozzle 25' to be discharged into the outlet pipe I I. The gases intraversing the nozzle 25 expand slightly, and with their dischargetherefrom, they produce a suction in the body adjacent the outlet whichoperates to withdraw the other gases from the body tocombine with theother gases for final discharge from the muffler.

In the use of my muffler with high speed engines, the pipe l8 and thefunnel members 24 and 25 are all that is required to effect completeejection of all gases from the body B without setting up appreciableback pressure in the exhaust pipe P and yet effectively mufiling theexplosions.

However, in the instance of a. low speed heavv duty engine, the pipe 20is employed in conjunction with the other elements to function as I willnow describe.

Because of the high velocity of those gases traversing the pipe l8 thereis produced in the port 22 an intensive suction which functions to drawthe gases entering the pipe 20 into the pipe l8. By virtue of the sizeand location of the port, and the length and form of the pipe 20,

gases will accumulate in the pipe 20 to produce an elastic mediumagainst which the succeeding gases impinge. Their impingement againstthis fluid medium is cushioned by reason of its elasticity, and, inconsequence, very little if any back pressure is generated in respect tothe gases in the exhaust pipe P.

With low speed engines the exhaust pulsations are slow and of largevolume in point of gas, and, hence, gas would not traverse the pipe l8in quantity sufiicient to produce a suction of the requisite intensityto cause all gases to be drawn from the muffler. However, by theprovision of the pipe 20 and the port 22, the gases entering the pipe 20are pushed and drawn into the pipe l8 to such an extent as to set up acontinuous gas flow through the pipe I8 thereby producing anuninterrupted suction at the nozzle 26 which acts constantly to ejectthe gases from the muffler and thus prevent back pressure building up inthe exhaust pipe. 1

As previously expressed herein, my invention also includes a device bywhich a part of the exhaust gases can be delivered to the enginecylinders for the purpose of utilizing the unburnt parts of the gases asfuel, and to thereby lessen the total amount of fresh fuel consumed bythe engine.

This device comprises a pipe P communicating at one end with the intakemanifold M of the engine, as'shown in Fig. 1. At the other end the pipeextends into the muffler body B, as shown in Fig. 2, with its innerextremity bent back upon itself so that its open end is facing the inletend of the mufiier.

In the line of the pipe P is a valve element V (Fig. 5) which includes abody 21 having a port 28 formed with a seat 29 for a-valve 30. The valvehas a stem 3| movable in a guide 32, and a spring 33 urges the valve offof its 'seat to open the port 28. A screw plug 34 permits access to thevalve, and it is provided with a stop pin 35 which defines the openposition of the valve.

In the operation of the device, the intensive suction produced in thebody B combines with the suction produced in the intake manifold whichcauses the exhaust gases to be drawn into the manifold where they mixwith the fresh fuel from the carburetor for final delivery to the valve30 is mounted so as to be responsive to this 10 suction and in such amanner that with the engine operating at an idling speed the valve isheld nearly or fully closed by the suction but as the engine increasesfrom this minimum the suction decreases and the spring 33 operates to 15open the valve, the valve being completely open when the speed is at amaximum.

.Thus the valve operates automatically to control the amount of exhaustgases admitted to the intake manifold in accordance with the speed 20 ofthe engine. By this mode of operation stalling of the engine when idlingor at a relatively low I speed, is prevented by admitting only a smallquantity of exhaust gases, or in some cases no exhaust gases. 25

My device, aside from utilizing the exhaust gases as fuel, providesanother advantage. Bearing in mind that the pressure of the exhaustgases is communicated to the intake manifold, it is of necessitycommunicated to the com- 30 bustion chambers of the cylinders. As aconsequence, the fluid pressure on the pistons is greatly increasedduring their intake strokes, and hence, the resistance offered tomovement of the pistons during their suction stroke is greatlydecreased. 35

In this manner the power output of the engine is further increased.

Although I have herein shown and described only one form of muffler andone form of device for utilizing exhaust gases as fuel, each embody- 4ing my invention, it is to be understoodthat various changes andmodifications may be made herein without departing from the spirit of myinvention and the spirit and scope of the appended claim.

I claim:

A mufller comprising; a body having a gas inlet and an alined gasoutlet; a pipe in the body having its inlet end extending through thegas inlet of the body and of a diameter less than that of the inlet toreceive a portion of the gas before it enters the body so that itsoriginal high velocity is maintained while traversing the pipe, theremainder of the gas passing into the body around the pipe and expandingto a lower velocity and 5 pressure than the gas traversing the pipe, andthe outlet end of the pipe being spaced from but alined with the gasoutlet of the body so that the high velocity gas as 'discharged from thepipe produces in the body a negative pressure or 6 suction to withdrawthe low velocity gas from the body and discharge it into atmosphere; aconical member disposed in the body to surround said pipe with its largeend facing the inlet to receive at least a part of the gas entering thebody around the pipe; a port in-saicl pipe adjacent the small end of theconical member: and funnel members interposed between the outlet end ofthe pipe and the gas outlet of the body, said members having theirsmaller ends alined with the pipe, facing the gas outlet and increasingin diameter toward the gas outlet.

' JULIUS C. KITTELL.

